A Maryland mother who was found dead two days ago died as a result of being stabbed and beaten, police said Friday. Her 11-year-old son remains missing.

The woman's husband was charged with first-degree murder after her body was discovered.

Curtis Lopez, 45, was arrested Thursday morning in Charlotte, North Carolina, said Chief Tom Manger of the Montgomery County, Maryland, police.

An Amber Alert has been issued for the boy, 11-year-old William McQuain, police said.

The case began Wednesday afternoon when a friend of the boy's mother reported her missing, saying he had not seen her for about two weeks and that he was concerned for her welfare, Manger said. Police learned her son had not been in school since September 30.

When detectives arrived at the woman's home in Germantown, they found Jane McQuain, 51, dead in her bedroom, Manger said. Her son was not there and the woman's vehicle, a Honda CRV, was gone.

Lopez had been known to frequent McQuain's residence but did not appear to live there, Manger said. Witnesses told police they saw him recently at the home, removing property and loading it into McQuain's Honda, he said.

The car was found Thursday morning, but police would not reveal where.

Jane McQuain was probably dead for 10 to 12 days before police found her, Manger said.

Police believe Lopez may have had a residence in North Carolina, Capt. Paul Starks of the Montgomery County police told CNN, but they have few other details linking him to the area.

William is described as a light-skinned African-American, about 5 feet tall and weighing about 85 pounds.